In recent years, active research and development regarding organic electroluminescent devices (the organic electroluminescent device being sometimes referred to as “luminescent device”, “organic EL device”, or “EL device” in the invention) are carried out because light emission with a high luminance is obtained at low-voltage driving. In general, the organic EL device is constituted of counter electrodes having a luminescent layer or a plurality of organic layers containing a luminescent layer put therebetween. The organic EL device utilizes light emission from excitons formed by recombination of electrons injected from a cathode and holes injected from an anode in a luminescent layer, or utilizes light emission from excitons of other molecule formed by energy transfer from the foregoing excitons.
In an organic luminescent device comprising an anode, a cathode and an organic compound film, there is reported an organic luminescent device in which the organic compound film includes a hole transport region comprising a hole transport material and an electron transport region comprising an electron transport layer, a mixed region containing both the hole transport material and the electron transport material is provided between the hole transport region and the electron transport region, and a material capable of causing red light emission from the triplet excitation state is added in the mixed region (see, for example, JP-A-2002-305085). However, any means for improving efficiency and durability of blue and green EL devices is not disclosed at all.